c# - 动态创建实体实例并添加新条目

Question

请考虑以下示例:

public override int SaveChanges()
{
    foreach (var auditableEntity in ChangeTracker.Entries<ISomething>())
    {
        if (auditableEntity.State == EntityState.Added)
        {
            //Create a new instance of the same entity type. 
            //I don't know which one will be. They just have the same interface.
            var newEntity = ?; //???Reflection???

            //ISomething known properties.
            newEntity.propX = "1";
            newEntity.propY = "2";

            //Invoke Add method.
            ??.Add(newEntity); 
        }
    }

    return base.SaveChanges();
}

我需要在 SaveChanges() 方法期间动态创建我所有 ISomething 实体的实例，以便添加新的特定条目

我们非常欢迎任何帮助。

问候

Answer 1

您可以使用非通用 DbContext.Set Method (Type)得到相应的非通用 DbSet .然后你可以使用Create方法创建相同类型的新实例和Add添加方法。

像这样:

var entityType = auditableEntity.Entity.GetType();
var dbSet = Set(entityType);
var newEntity = (ISomething)dbSet.Create();

//ISomething known properties.
newEntity.propX = "1";
newEntity.propY = "2";

dbSet.Add(newEntity);